A hydraulic connector hose is a tube that transfers fluids under pressure from one place to another. A hydraulic hose is a composite structure primarily made of rubber or thermoplastic and steel reinforcement. The steel reinforcement may include wire that is tightly wound spirally along the length of the hose so as to form a steel shell or it might be braided across the length of the hose for higher strength. The outermost covering is usually made of polymer material that helps protect the inner layers from harsh environments. Hydraulic hoses operate from a very low pressure to extremely high pressure depending on the applications. Hydraulic hoses are used in a variety of industries like heavy-machinery, household appliances etc and environments. In certain situations, especially in heavy machinery, the health of a hose is critical.
A hydraulic hose has a finite service life and all hoses eventually fail due to various factors like external damage, multi-plane bending, operating conditions, etc. The damage to a hose carrying such high pressures can lead to serious injury or death of an operator. Hence, monitoring the health of the hose becomes critical.
Conventional technology depicted by U.S. Pat. No. 7,555,936 to Purdue Research Foundation and PCT Publication No. WO 2010/004418 to Eaton Corporation generally uses the hydraulic hose as a sensor. For example, the above listed references use the principle of capacitance measurement wherein the capacitance of the hose is measured and used as the health indicator of the hose. Problems with such methods include: hose metal layers may come in contact with each other due to crimping, for example; does not consider a hose with other than two metal layers; and discounts the damage to the hose caused from a foreign object.